Thread: Sharpening stainless steel knives

The real trick with stainless is to not let it approach dull in the first place. Stainless will clog a stone faster than carbon due to the alloying elements. The chromium in particular creates problems as it binds with the carbon creating really wear resistant carbides (as an aside stainless isn't necessarily harder than carbon steel but it tends to be more wear resistant).

If the knives aren't too dull, I use oil stones and clean them more often. If they are dull, I either use a coarse man made stone first (the only reason I own a man made stone) or use cardboard wheels on a bench grinder.

ron

I would take it to the grinder. I have a Tormek and I have exceptionally sharp knives. My mother-in-law nearly soiled herself when she came over and chopped a potatoe!

I've had a similar problem
tried a file & it seemed to get a result... sort of.
I go to the white wheel on the grinder these days.
one problem with knives is that the blades flex & that makes everything hard.

If I was a chef ir similar I would get fussy, but our knives go in the dishwasher so the grinder is OK.
cheers

Originally Posted by markharrison

My mother-in-law nearly soiled herself when she came over and chopped a potatoe!

I'd pay good money to get a result like that with my MIL. Or maybe make it a little bit sharper still to remove the 'nearly'.

Hi this is an extract of some info that was given ot me as an apprentice about 30 odd years ago don't know if it will help.


The Expert's Way to Sharpen<o></o>
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A not‑serrated knife blade is bevelled on each side so that its cutting edge forms a "V". That cutting edge can be as thin as 11400 of a millimetre (1110.000 of an inch). Every use wears down the bevelled edges and dulIs the knife. To keep your knives in good order, you should reset and abrade the edges with a sharpening steel before each use.<o>
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The professional way to accomplish this is as follows: hold the steel in one hand, pointing it away from you; hold the knife in your other hand with the flat of the blade at about a 20° angle to the steel and with the edge facing you. Then starting at the tip of the steel, draw the knife blade diagonally across the shaft towards you. At the end of a continuous, smooth stroke the point of the knife should be half‑way up the steel. Then hold the knife under the steel at the same angle with the edge facing you and draw it towards you along the underside. Repeat both steps several times. Be sure to stroke lightly ‑ the steel will work with every little pressure.
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Eventually your realignment will wear away the original bevels on the blade and it will require regrinding. For this chore, you may want to take your good knives to a professional. But if you are a do‑it‑yourselfer, you can learn how to regrind them ‑ with practice, you can regrind a knife in less than 10 minutes.<o></o>

You will need a corundum whetstone with both coarse and fine sides, an extremely finegrained stone made of novaculite, and a natural ‑ leather strop. The stones should be flat rectangles that you can set on a table. Submerge them overnight in mineral oil and wipe off the excess; the remaining oil catches any metal fillings that become embedded in the stones and dull their surfaces.<o></o>

A chefs knife requires a 30° bevel (15° on each side); tomato, paring and boning knives 25° to 30°; butcher, filleting and carving knives, as well as meat slicers, 18° to 24°.To achieve those final bevels, the angle of stroke on each side of the blade should be half of your goal.<o></o>

Use the corundum stone first and proceed slowly. Lay the knife blade flat on the coarse side of the whetstone and tip it up until it is at the angle you want. Make a slow, curving sweep away from you and across the stone, so that one side of the entire blade touches the stone in a single motion. Turn the blade over so that the other side of the edge touches the stone at the same angle. Pull it towards you in an arc.<o></o>

Repeat several times for each side. Hold the edge of the knife to the light. If you see reflected light along the bevel you must work some more, until the sides of the bevel do not reflect light any longer.<o></o>

There will now be scratches that must be polished off. Turn the whetstone so that its fine surface is on top. Then, using the same angle and the same technique, give the knife about 10 strokes per side.<o></o>

The next step is to polish the edges on the novaculite stone. Give the blade 10 strokes per edge at the same angle. Now the edges should have a dull gleam ‑ and no scratches ‑ and you are ready for a final polishing.<o></o>

Strop the knife on a leather wipe it, edge down, 10 times on each side ‑ first on the rough side of the belt, then on the smooth.<o></o>

Thanks for your thoughts. Robbie, I appreciate your detailed description of knife sharpening, it makes sense except that I'm not getting far with the first stone part. The grinder with the white wheel is too aggresive, so still thinking that a belt sander with a finer grit is the way to go.

Hi Tiger,
Robbiewy posted an excellent article on sharpening knives.

I keep all my knives sharp, sharpening them regularly. All the stones I use are from Carbatec Brisbane, for sharpening I have an 800, a 2000, a 4000 and a natural stone - all these are waterstone and everyone is a King stone except the natural stone which is Chinese. I suggest you buy your stones from a woodwork shop, the same stones sold in some knife shops can be up to 100% more expensive.
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The steps I follow are similar to those set out by Robbiewy.

If you need to set the knife at the correct angle, you can use either the metal clip off a stationary folder (not one with the handles) and clip it onto the back of the knife. If you would like the professional version then check with your local knife shops as "Global Knives" make a stainless steel clip for the same purpose.

When you have sharpened your knives, they will still feel as though the edge is dull if you have residue from the stone on your fingers, but once your hands are clean you will be impressed by your efforts.

Finally, buy a good "steel" to maintain the edge.

Good luck.

I sharpened my "F. Dick" knife in the Record whetstone and it has a brilliant edge, I doubt it is stainless but a high quality carbon steel.

I use a dual sided silicone carbide stone. Can't claim any science to it but the knives are sharp enough to pass the soft tomato test.

Originally Posted by Iain

I sharpened my "F. Dick" knife in the Record whetstone and it has a brilliant edge, I doubt it is stainless but a high quality carbon steel.

F Dick Knifes are a German brand knife a high quality stainless steel I think they have slightly more nickel in the steel and are a little harder to sharpen but hold an edge longer.

Ok.... can I hit you blokes up with a specific question?

I have a 15 year old "Titanium Stainless" alloy knife... its a work knife and its fantastic. Tough knife.... its a boot knife style or pushing dagger.

Can't sharpen it though... it wears the oilstones away, and I don't have access to a diamond stone at the moment... or anything else really.

Am I just missing a technique, or is this allow renown for being a bugger to sharpen?

And yep, I know how to sharpen a knife or blade... its just this one that is giving me trouble.

Geez Clinton,

You should get some wear when you sharpen, my waterstones wear a little, but if it excessively wears down your stone and is still blunt I don't have an answer . I could say you are not maintaining a constant angle but if you know how to sharpen a knife then I am wrong on this point.

My suggestion would be to go to a professional sharpener/knife shop and get advice from them, they may have what you require.
Given your location at the moment (Timor?) I don't have a current solution - but I will ask around.

Regards

Felixe.

thanks mate.
Yes, the metal is as tough as.... made from aircraft structural component scrap... be nice if one edge was sharp though....

Clinton - belt sander or file ?